Personal vehicles, such as may be used by handicapped persons, may be self-propelled and user-guidable, and, further, may entail stabilization in one or more of the fore-aft or lateral planes, such as when no more than two wheels are in ground contact at a time. More particularly, such vehicles may include one or more clusters of wheels, with wheels in each cluster capable of being motor-driven independently of the cluster in its entirety. One example of such a vehicle is described in U.S. Pat. No. 5,701,965, which is incorporated herein by reference. Since personal vehicles operate under stringent constraints of weight and power, the features of such vehicles are typically limited to those essential to the propulsion of the vehicle, with safety left largely in the hands of the operator, and comfort largely foregone. Vehicles of this sort may be more efficiently and safely operated employing mechanical features supplementary to those described in the prior art.